BIOL3003 - ADAPTIVE IMMUNITY 1 (L1) EXAM QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS VERIFIED

BIOL3003 - ADAPTIVE IMMUNITY 1 (L1) EXAM QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS VERIFIED CD8 T cell Cytotoxic T lymphocyte, kills virally infected cells CD4 T cell types Th1, Th2, Th17, Tfh, Treg CD4 Th1 cell function Activate infected macrophages to kill bacteria living inside macrophage (Listeria, Leishmania etc). Helps B Cells CD4 Th2 cell function Helps B cells to produce antibodies CD4 Th17 cell function neutrophil response, promote barrier integrity Tfh cell function helps B cells with isotype switching and antibody production T reg function suppress T cell responses Other types of T cells Natural killer T cells (NKT), Mucosal associated invariant T cells (MAIT), Gamma delta T cells NKT cells recognize glycolipids presented on CD1d (a protein similar to MHC) NKT cell features highly conserved TCR alpha chain (TCRValpha24/TCRJalpha18). NKT cells are a component of innate immunity and are a link to adaptive immunity NKT cells secrete IFN-g, IL-4 MAIT cells recognise vitamin B metabolite complexed to MR1. MR1 is a non-classical MHC molecule encoded in the genome. Riboflavin is the metabolite recognised (mammals do not have this biosynthetic pathway). Involved in bacteria and yeast immunity MAIT cell features highly conserved TCR alpha chain (TCRValpha7.2/TCRJalpha33) MAIT cells secrete IFN-g, TNF-a, IL-17 Gamma delta T cells recognise Not just peptides (lipids, glycolipids, phosphoantigens) Gamma delta T cell features CD4 and CD8 negative. Protects embryo before alphabeta T cells are ready. Gamma delta T cells secrete IL-17 Gamma delta T cells roles DC maturation, B cell help, IgE production, priming of alphabeta T cells via antigen presentation, growth factor production, lysis of infected cells Naïve T cells enter lymph node through high endothelial venule if no DC to present antigen, they leave through cortical sinus. If DC present antigen, they get activated, proliferate, turn into effector T cell